1. Field
A linear compressor is disclosed herein.
2. Background
In general, compressors may be mechanisms that receive power from power generation devices, such as electric motors or turbines, to compress air, refrigerants, or other working gases, thereby increasing a pressure of the working gas. Compressors are being widely used in home appliances or industrial machineries, such as refrigerators and air-conditioners.
Compressors may be largely classified into reciprocating compressors, in which a compression space, into and from which a working gas, such as a refrigerant, is suctioned and discharged, is defined between a piston and a cylinder to compress a refrigerant while the piston is linearly reciprocated within the cylinder; rotary compressors, in which a compression space, into and from which a working gas, such as a refrigerant, is suctioned and discharged, is defined between a roller, which is eccentrically rotated, and a cylinder to compress the refrigerant while the roller is eccentrically rotated along an inner wall of the cylinder; and scroll compressors, in which a compression space, into and from which a working gas, such as a refrigerant, is suctioned and discharged, is defined between an orbiting scroll and a fixed scroll to compress the refrigerant while the orbiting scroll is rotated along the fixed scroll. In recent years, among the reciprocating compressors, linear compressors having a simple structure in which a piston is directly connected to a drive motor, which is linearly reciprocated, to improve compression efficiency without mechanical loss due to switching in moving are being actively developed. Generally, such a linear compressor is configured to suction and compress a refrigerant while a piston is linearly reciprocated within a cylinder by a linear motor in a sealed shell, thereby discharging the compressed refrigerant.
The linear motor has a structure in which a permanent magnet is disposed between an inner stator and an outer stator. The permanent magnet may be linearly reciprocated by a mutual electromagnetic force between the permanent magnet and the inner (or outer) stator. Also, as the permanent magnet is operated in a state in which the permanent magnet is connected to the piston, the refrigerant may be suctioned and compressed while the piston is linearly reciprocated within the cylinder and then be discharged.
A linear compressor according to the related art is disclosed in Korean Patent Publication No. 10-2010-0112474. Referring to FIGS. 1 and 2 of the Korean Patent Application, in the case of a typical linear compressor, a frame and a cylinder are integrally formed in a closed container. More specifically, the cylinder is manufactured through magnetic casting, and then aluminum, a non-magnetic material, is insert-molded onto the outer circumferential surface of the cylinder to manufacture the frame.
The frame integrally formed with the cylinder may be coupled to a peripheral component, for example, a discharge valve assembly or a motor cover. In this case, a force (coupling force) applied when the frame is coupled to the discharge valve assembly or the motor cover may be applied to the cylinder.
When the coupling force is applied to the cylinder 3, the cylinder is deformed. In addition, when the deformation of the cylinder is significant, interference may occur due to the friction between the cylinder and the piston reciprocating in the cylinder.
As such, as interference occurs between the cylinder and the piston, there is a limitation in that interference occurs among a permanent magnet connected to the piston, an inner stator, and an outer stator, and thus, parts may be damaged. In addition, there are limitations in that due to the deformation of the cylinder, cracks may occur in the piston and the cylinder, and a compression gas may be externally leaked through the cracks.